Sulfonylhydrazines and their use as antineoplastic agents and as antitrypanosomal agents

ABSTRACT

Sulfonylhydrazines of the formula RSO 2  N(CH 2  CH 2  X)N(SO 2  CH 3 ) 2 , wherein R is an alkyl or an aryl and X is a halogen or OSO 2  Y, wherein Y is an alkyl or an aryl. Such sulfonylhydrazines are useful in treating cancer. 
     Methylating agents of the formula 
     (a) R&#39;SO 2  N(CH 3 )N(SO 2  CH 3 ) 2 , wherein R&#39; is an alkyl or an aryl and 
     (b) R&#34;SO 2  N(CH 3 )N(CH 3 )SO 2  R&#34;, wherein R&#34; is an alkyl or an aryl. 
     Such methylating agents are useful as antitrypanosomal and anticancer agents.

GOVERNMENT RIGHTS

This invention was made with United States government support underGrant CA-02817 from the United States Public Health Service. The UnitedStates government may have certain rights in the present invention.

This is a division of application Ser. No. 07/403,533, filed Sep. 6,1989, now U.S. Pat. No. 5,101,072.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to novel sulfonylhydrazines and theiruse as antineoplastic agents. The present invention also concernsmethylating agents, especially N-methyl-N-sulfonylhydrazines, and theiruse as antineoplastic and trypanocidal agents.

2. Background Information

The synthesis and anticancer activity of a series of1,2-bis(sulfonyl)-1-methylhydrazines was reported in K. Shyam, R. T.Hrubiec, R. Furubayashi, L. A. Cosby and A. C. Sartorelli, J. Med.Chem., 30, 2157-2161 (1987). Base-catalyzed decomposition to generatethe putative methylating species RSO₂ N═NMe was hypothesized to accountfor the observed biological activity.

Trypanosomes of the brucei group are flagellated protozoa which producelethal infections in humans and domestic mammals throughout much ofsub-Saharan Africa. (M. Katz, D. D. Despommier and R. W. Gwadz,Parasitic Diseases, Springer-Verlag, New York (1982); R. Allsopp, D.Hall and T. Jones, New Scientist, 7, 41-43 (1985); C. A. Hoare, Adv.Parasitol., 5, 47-91 (1967)). With the exception ofalpha-difluoromethylornithine (DFMO), the trypanocidal drugs currentlyin use have been available for 25 to 80 years. Current treatment ofearly-stage infections consists of suramin for T. rhodesiense andpentamidine for T. gambiense (S. R. Meshnick, "The Chemotherapy ofAfrican Trypanosomiasis", In: Parasitic Diseases, J. M. Mansfield, ed.,Marcel Dekker, Inc., New York (1984); F.I.C. Apted, Manson's TropicalDiseases, 18th edition, Bailliere Tindall, Eastbourne (1983), pp. 72-92;W. E. Gutteridge and G. H. Coombs, The Biochemistry of ParasiticProtozoa, Macmillan, London (1977), pp. 1-25).

These therapies require approximately six weeks of hospitalization dueto drug toxicity. The only drug available for late-stage sleepingsickness is melarsoprol (S. R. Meshnick, supra). This drug has seriousside-effects and up to 5% of patients die due to drug toxicity. Suramin,pentamidine and melarsoprol are all administered by intravenousinjection. Recently, DFMO has been shown to be effective againstearly-stage sleeping sickness in man and animals. However, there aredoubts as to its efficacy in late-stage disease unless it is used incombination with other less desirable agents such as bleomycin (P. P.McCann, G. J. Bacchi, A. B. Clarkson, Jr., J. R. Seed, H. C. Nathan, B.O. Amole, S. H. Hutner and A. Sjoerdsma, Medical Biol., 59, 434-440(1983); A. B. Clarkson, Jr., C. J. Bacchi, G. H. Mellow, H. C. Nathan,P. P. McCann and A. Sjoerdsma, Proc. Natl. Acad. Sci. USA, 80, 5729-5733(1983)). Therefore, better drugs are needed to treat trypanosomiasis.

SUMMARY OF THE INVENTION

The present invention concerns sulfonylhydrazine compounds of theformula RSO₂ N(CH₂ CH₂ X)N(SO₂ CH₃)₂, wherein R is an alkyl having 1 to10 carbon atoms, preferably 1 to 6 carbon atoms and preferably methyl,ethyl, n-propyl, i-butyl or n-butyl, cycloalkyl, preferably having 3 to6 carbon atoms, or an aryl, preferably having 6 to 12 carbon atoms, forexample, phenyl, 4-tolyl, 4-methoxyphenyl, 4-chlorophenyl,4-bromophenyl, 4-nitrophenyl, naphthyl or biphenyl and X is a halogenselected from the group consisting of F, Cl, Br and I, especially Cl, Bror I, or OSO₂ Y, wherein Y is an unsubstituted or substituted alkylhaving 1 to 10 carbon atoms or an unsubstituted or substituted aryl. Yis preferably methyl, but non-limiting examples of Y also include ethyl,propyl, isopropyl, trichloromethyl, trifluoromethyl, phenyl, p-tolyl,p-methoxyphenyl, p-chlorophenyl and other substituted phenyls. Apreferred compound is CH₃ SO₂ N(CH₂ CH₂ Cl)N(SO₂ CH₃)₂.

The present invention also relates to a method of treating cancer (e.g.,leukemias, lymphomas, breast carcinoma, colon carcinoma and lungcarcinoma), in a warm-blooded animal patient, e.g., a human, byadministering to such patient an antineoplastic effective amount of theaforesaid sulfonylhydrazine.

The present invention is also directed to the following two classes ofmethylating agents:

(1) R'SO₂ N(CH₃)N(SO₂ CH₃)₂, namely1,2,2-tris(sulfonyl)-1-methylydrazines, wherein R' is an alkyl having 1to 10 carbon atoms, preferably 1 to 6 carbon atoms and preferablymethyl, ethyl, n-propyl, i-propyl, n-butyl or i-butyl, cycloalkyl,preferably having 3 to 6 carbon atoms, or an aryl, preferably having 6to 12 carbon atoms, for example, phenyl, 4-tolyl, 4-methoxyphenyl,4-chlorophenyl, 4-bromophenyl, 4-nitrophenyl, naphthyl or biphenyl.

(2) R"SO₂ N(CH₃)N(CH₃)SO₂ R", namely1,2-bis(sulfonyl)-1,2-dimethylhydrazines, wherein R" is an alkyl having1 to 10 carbon atoms, preferably 1 to 6 carbon atoms and preferablymethyl, ethyl, n-propyl, i-propyl, n-butyl or i-butyl, cycloalkyl,preferably having 3 to 6 carbon atoms, or an aryl, preferably having 6to 12 carbon atoms, for example, phenyl, 4-tolyl, 4-methoxyphenyl,4-chlorophenyl, 4-bromophenyl, 4-nitrophenyl, naphthyl or biphenyl.

The present invention further relates to a method of treatingtrypanosomiasis in patients, e.g., warm-blooded animals, such as humans,horses, sheep, goats, swine, camels or cattle, by administering to suchpatients a trypanocidal effective amount of a methylating agent asdescribed above.

The present invention also concerns a method of treating trypansomiasisin a warm-blooded animal patient comprising administering to saidpatient a trypanocidal effective amount of a compound capable ofgenerating a methylating agent of the formula CH₃ N=NX', wherein X' is aleaving group, e.g., OH or SO₂ R'", wherein R'" is an alkyl or an aryl,more particularly an unsubstituted or substituted alkyl having 1 to 10,preferably 1 to 6, carbon atoms or an unsubstituted or substituted aryl,including other species capable of generating methyl radicals (CH₃ •),diazomethane (CH₂ N₂) or methyldiazonium (CH₃ N₂ ⁺). Non-limitingexamples of such compounds which generate CH₃ N═NX' includeN-methyl-N-nitrosourea,5-(3,3-dimethyl-1-triazenyl)-1H-imidazole-4-carboxamide, streptozotocinand 1,2-bis(sulfonyl)-1-methylhydrazines.

Typical substituents for the substituted alkyl and substituted aryl forR', R" and R'" in the above formulas include halogen, e.g., chlorine,fluorine or bromine, hydroxy and nitro. Furthermore, the aryl can besubstituted by C₁ -C₁₀ alkyl or C₁ -C₁₀ alkoxy.

The present invention is also directed to a method of treating cancer ina warm-blooded animal patient, e.g., human patient, comprisingadministering to such patient an antineoplastic effective amount of amethylating agent selected from the group consisting of

(a) R'SO₂ N(CH₃)N(SO₂ CH₃)₂, wherein R' is an alkyl having 1 to 10carbon atoms or an aryl, for example, phenyl, 4-tolyl, 4-methoxyphenyl,4-chlorophenyl, 4-bromophenyl, 4-nitrophenyl, naphthyl or biphenyl, and

(b) R"SO₂ N(CH₃)N(CH₃)SO₂ R", wherein R" is an alkyl having 1 to 10carbon atoms or an aryl, for example phenyl, 4-tolyl, 4-methoxyphenyl,4-chlorophenyl, 4-bromophenyl, 4-nitrophenyl, naphthyl or biphenyl.

DETAILED DESCRIPTION OF THE INVENTION Synthesis

1-Methyl-1,2,2-tris(methylsulfonyl)hydrazine was synthesized by reactingmethylhydrazine with an excess of methanesulfonyl chloride in pyridine.

1,2-Bis(methylsulfonyl)-1,2-dimethylhydrazine was prepared by reactingmethanesulfonyl chloride with 1,2-dimethylhydrazine dihydrochloride inapproximately a 2:1 molar ratio in pyridine.1-(2-Chloroethyl)-1,2,2-tris(methylsulfonyl)hydrazine was synthesized asshown in the following reaction scheme: ##STR1##

The use of lithium bromide and potassium iodide in lieu of lithiumchloride in the second step gave the 2-bromoethyl and the 2-iodoethylanalogues, respectively.1-Arylsulfonyl-1-(2-chloroethyl)-2,2-bis(methylsulfonyl)hydrazines weresynthesized by reacting the corresponding1-arylsulfonyl-1-(2-methylsulfonyloxy)ethyl-2,2-bis(methylsulfonyl)hydrazinewith lithium chloride in acetone. The (methylsulfonyloxy)ethyl compound,in turn, was prepared by reacting the appropriate1-arylsulfonyl-1-(2-hydroxyethyl)hydrazide with an excess ofmethanesulfonyl chloride in pyridine. The1-arylsulfonyl-1-(2-hydroxyethyl)hydrazides were prepared by methodologyanalogous to that described by K. Shyam, R. T. Hrubiec, R. Furubayashi,L. A. Cosby and A. C. Sartorelli, J. Med. Chem., 30, 2157-2161 (1987).

Mechanisms of Activation

The 1,2,2-tris(sulfonyl)-1-methylhydrazines are believed to undergospontaneous hydrolysis in aqueous solutions at neutral pH to generate1,2-bis(sulfonyl)-1-methylhydrazines as shown below. ##STR2##

In the case of 1,2,2-tris(methylsulfonyl)-1-methylhydrazine, thisreaction occurs slowly. A 50 μM solution of this compound hydrolyzes atan initial rate of 1% per minute in phosphate buffered saline (pH 7.6)at 37° C.

Hydrolysis is expected to occur preferentially at N-2 to generate the1,2-bis(sulfonyl)-1-methylhydrazine. The sulfonic acid and1,2-bis(sulfonyl)-1-methylhydrazine that are generated are both ionizedunder these conditions. The release of protons can be used to follow thedecomposition of these and related compounds. The release of protons canbe assayed by following the decrease in absorbance at 560 nm of a weaklybuffered (1 mM potassium phosphate) phenol red (21 mg/l) solution;initial pH 7.6 at 37° C. The assay can be calibrated using HClstandards.

The 1,2-bis(sulfonyl)-1-methylhydrazine anions are believed to decomposeunder these conditions by a two-step process, generating the putativealkylating species RSO₂ N═NCH₃ as an intermediate. The intermediate canmethylate nucleophiles, such as water and other biomolecules as shownbelow.

    RSO.sub.2 e,ovs/N/ --N(CH.sub.3)SO.sub.2 R→RSO.sub.2 N═NCH.sub.3 +RSO.sub.2.sup.-

    RSO.sub.2 N═NCH.sub.3 +H.sub.2 O→RSO.sub.2.sup.- +N.sub.2 +CH.sub.3 OH+H.sup.+

The reaction of 1,2-bis(sulfonyl)-1-methylhydrazine with water at pH7.4-7.6 at 37° C. can be followed by proton release and/or methanolgeneration. Methanol generation can be assayed using alcohol oxidase andmeasuring the resultant O₂ consumption using a Gilson oxygraph. Thisassay can be calibrated using methanol standards. The reaction of1,2-bis(sulfonyl)-1-methylhydrazine with water is relatively fast [a 50μM solution of 1,2-bis(methylsulfonyl)-1-methylhydrazine decomposes atan initial rate of 12-15% per minute in phosphate buffered saline (pH7.6) at 37° C.] compared to the hydrolysis of1,2,2-tris(methylsulfonyl)-1-methylhydrazine. RSO₂ N═NMe may alsodecompose by a free radical mechanism to a smaller extent and methylateby the generation of methyl radicals.

The 1-(2-chloroethyl)-1,2,2-tris(methylsulfonyl)hydrazine would beexpected to undergo hydrolysis and base-catalyzed elimination in amanner analogous to the 1,2,2-tris(sulfonyl)-1-methylhydrazines. Thechloroethylating species generated in this case, ClCH₂ CH₂ N═NSO₂ CH₃,would be expected to act as a bifunctional alkylating agent as shownbelow. ##STR3## wherein Nu and Nu' are biological nucleophiles, e.g.,primary or secondary amines, sulfhydryl groups or carboxy groups.

Compounds of the general structure R"SO₂ N(CH₃)N(CH₃)SO₂ R" may act asmethylating agents by several mechanisms including:

(i) hydrolysis to generate 1,2-dimethylhydrazine followed by oxidationto give 1,2-dimethyldiazene as follows:

    RSO.sub.2 N(CH.sub.3)N(CH.sub.3)SO.sub.2 R→CH.sub.3 NHNHCH.sub.3 →CH.sub.3 N═NCH.sub.3

    CH.sub.3 N═NCH.sub.3 →CH.sub.3.sup.• +N.sub.2 +CH.sub.3.sup.•

(ii) N-demethylation to give 1,2-bis(sulfonyl)-1-methylhydrazine.

Formulations and Modes of Administration

The invention further provides pharmecutical compositions containing asan active ingredient the aforementioned sulfonylhydrazines, theaforementioned 1,2,2-tris(sulfonyl)-1-methylhydrazine, or theaforementioned 1,2-bis(sulfonyl)-1,2-dimethylhydrazine in the form of asterile and/or physiologically isotonic aqueous solution.

The invention also provides a medicament in dosage unit form comprisingthe aforementioned sulfonylhydrazines, the aforementioned1,2,2-tris(sulfonyl)-1-methylhydrazine, or the aforementioned1,2-bis(sulfonyl)-1,2-dimethylhydrazine, all hereinafter referred to asthe "active ingredient" or "active compound".

The invention also provides a medicament in the form of tablets(including lozenges and granules), caplets, dragees, capsules, pills,ampoules or suppositories comprising the aforementionedsulfonylhydrazine, the aforementioned1,2,2-tris(sulfonyl)-1-methylhydrazine or the aforementioned1,2-bis(sulfonyl)-1,2-dimethylhydrazine, all hereinafter referred to asthe "active ingredient" or "active compound".

"Medicament" as used herein means physically discrete coherent portionssuitable for medical administration. "Medicament in dosage unit form" asused herein means physically discrete coherent units suitable formedical administration, each containing a daily dose or a multiple (upto four times) or a sub-multiple (down to a fortieth) of a daily dose ofan active compound of the invention in association with a carrier and/orenclosed within an envelope. Whether the medicament contains a dailydose, or for example, a half, a third, or a quarter of a daily dose willdepend on whether the medicament is to be administered once, or forexample, twice, three times, or four times a day, respectively.

The pharmaceutical compositions according to the invention may, forexample, take the form of suspensions, solutions and emulsions of theactive ingredient in aqueous or non-aqueous diluents, syrups,granulates, or powders.

The diluents to be used in pharmaceutical compositions (e.g.,granulates) adapted to be formed into tablets, dragees, capsules andpills may include one or more of the following: (a) fillers andextenders, e.g., starch, sugars, mannitol and silicic acid; (b) bindingagents, e.g., carboxymethyl cellulose and other cellulose derivatives,aliginates, gelatine and polyvinyl pyrrolidone; (c) moisturizing agents,e.g., glycerol; (d) disintegrating agents, e.g., agar-agar, calciumcarbonate and sodium bicarbonate; (e) agents for retarding dissolution,e.g., paraffin; (f) resorption accelerators, e.g., quaternary ammoniumcompounds; (g) surface active agents, e.g., cetyl alcohol, glycerolmonostearate; (h) adsorptive carriers, e.g., kaolin and bentonite; (i)lubricants, e.g., talc, calcium and magnesium stearate and solidpolyethylene glycols.

The tablets, dragees, capsules, caplets and pills formed from thepharmaceutical compositions of the invention can have the customarycoatings, envelopes and protective matrices, which may containopacifiers. They can be so constituted that they release the activeingredient only or preferably in a particular part of the intestinaltract, possibly over a period of time. The coatings, envelopes andprotective matrices may be made, for example, from polymeric substancesor waxes.

The active ingredient can also be made up in microencapsulated formtogether with one or several of the above-mentioned diluents.

The diluents to be used in pharmaceutical compositions adapted to beformed into suppositories can, for example, be the usual water-solublediluents, such as polyethylene glycols and fats (e.g., cocoa oil andhigh esters, [e.g., C₁₄ -alcohol with C₁₆ -fatty acid]) or mixtures ofthese diluents.

The pharmaceutical compositions which are solutions and emulsions can,for example, contain the customary diluents such as solvents,solubilizing agents and emulsifiers. Specific non-limiting examples ofsuch diluents are water, ethyl alcohol, isopropyl alcohol, ethylcarbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propyleneglycol, 1,3-butylene glycol, dimethylformamide, oils (for example,ground nut oil), glycerol, tetrahydrofuryl alcohol, polyethylene glycolsand fatty acid esters of sorbitol or mixtures thereof.

For parenteral administration, solutions and emulsions should be sterileand, if appropriate, blood-isotonic.

The pharmaceutical compositions which are suspensions can contain theusual diluents, such as liquid diluents, e.g., water, ethyl alcohol,propylene glycol, surface-active agents (e.g., ethoxylated isostearylalcohols, polyoxyethylene sorbite and sorbitane esters),microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agarand tragacanth or mixtures thereof.

All the pharmaceutical compositions according to the invention can alsocontain coloring agents and preservatives, as well as perfumes andflavoring additives (e.g., peppermint oil and eucalyptus oil) andsweetening agents (e.g., saccharin and aspartame).

The pharmaceutical compositions according to the invention generallycontain from 0.5 to 90% of the active ingredient by weight of the totalcomposition.

The pharmaceutical compositions and medicaments according to theinvention can also contain other pharmaceutically active compounds.

The discrete coherent portions constituting a medicament according tothe invention will generally be adapted by virtue of their shape orpackaging for medical administration and may be, for example, any of thefollowing: tablets (including lozenges and granulates), pills, dragees,capsules, suppositories and ampoules. Some of these forms may be made upfor delayed release of the active ingredient. Some, such as capsules,may include a protective envelope which renders the portions of themedicament physically discrete and coherent.

The preferred daily dose for administration of the medicaments of theinvention is 60 to 600 mg/square meter of body surface per day of activeingredient. Nevertheless, it can at times be necessary to deviate fromthese dosage levels, and in particular to do so as a function of thenature of the human or animal subject to be treated, the individualreaction of this subject to the treatment, the type of formulation inwhich the active ingredient is administered, the mode in which theadministration is carried out and the point in the progress of thedisease or interval at which it is to be administered. Thus, it may insome cases suffice to use less than the above-mentioned minimum dosagerate, while in other cases the upper limit mentioned must be exceeded toachieve the desired results. Where larger amounts are administered, itmay be advisable to divide these into several individual administrationsover the course of a day.

The production of the above-mentioned pharmaceutical compositions andmedicaments is carried out by any method known in the art, for example,by mixing the active ingredient(s) with the diluent(s) to form apharmaceutical composition (e.g., a granulate) and then forming thecomposition into the medicament (e.g., tablets).

This invention provides a method for treating the above-mentioneddiseases in warm-blooded animals, which comprises administering to theanimals an active compound of the invention alone or in admixture with adiluent or in the form of a medicament according to the invention.

It is envisaged that the active compounds will be administeredperorally, parenterally (e.g., intramuscularly, intraperitoneally,subcutaneously, or intravenously), rectally, or locally, preferablyorally or parenterally, especially perlingually or intravenously.Preferred pharmaceutical compositions and medicaments are, therefore,those adapted for administration, such as oral or parenteraladministration. Administration in the methods of the invention arepreferably oral administration or parenteral administration.

Treatment of Trypanosomiasis

One aspect of the present invention is the treatment of trypanosomiasisby administration of methylating agents. Such methylating agents areeffective against T.rhodesiense and T.gambiense, which cause fataldiseases in man, and also against T.brucei, T.evansi and T.equiperdum,which are of veterinary importance (C. A. Hoare, Adv. Parasitol., 5,47-91 (1967)).

Some methylating agents for use in the present invention are describedin K. Shyam, R. T. Hrubiec, R. Furubayashi, L. A. Cosby and A. C.Sartorelli, J. Med. Chem., 30, 2157-2161 (1987).

Non-limiting examples of methylating agents for use in the presentinvention include CH₃ NHNH₂, CH₃ NHNHCH₃, CH₃ SO₂ N(CH₃)NHSO₂ CH₃, CH₃SO₂ N(CH₃)NHSO₂ C₆ H₄ --p--OCH₃, (CH₃)₂ SO₄, CH₃ SO₂ OCH₃,N-methyl-N-nitrosourea, procarbazine,5-(3,3-dimethyl-1-triazenyl)-1H-imidazole-4-carboxamide andstreptozotocin.

Thirty-day "cures" of mice bearing T.rhodesiense were obtained with someof these agents at single dose levels which produced no overt signs oftoxicity.

In general, compounds lacking a reactive methyl group, but structurallyidentical to the corresponding N-methyl analogues in all other respects,or containing the methyl group, but lacking good leaving groups, areinactive as trypanocides (see Table III hereinbelow). The kinetics ofthe loss of activity of methylating agents upon the "aging" of anaqueous solution correlates well with the kinetics of methanolgeneration, a measure of the spontaneous breakdown of these agents togenerate the reactive methyl group. These findings provide strongevidence that methylation is essential for the observed biologicalactivity of these compounds.

Methylating agents appear to have two major effects on trypanosomes,depending upon the dose level. At high levels, cytokinesis appears to beinhibited almost immediately and the cells are transformed intotransitional forms containing multiple nuclei and kinetoplasts. Thesecells disappear from the bloodstream in 48 to 72 hours. Whenadministered at repetitive low doses, methylating agents induce theentire population to differentiate into short-stumpy forms (short-stumpyforms cannot differentiate further unless they are taken up by a feedingtsetse fly or placed in appropriate culture conditions), as judged bymorphology, NADH diaphorase positivity and other biochemical andphysiological criteria. Short-stumpy forms are non-dividingdifferentiated cells and are not infective to the mammalian host. Thelatter property may make these agents useful biochemical tools in thestudy of differentiation in trypanosomes, since, with these compounds,it is possible to induce the entire population of trypanosomes todifferentiate in a moderately synchronous manner and through thisapproach early events in the differentiation process can be studied.Both single high dose regimens and repetitive low doses can result incures using a number of the methylating agents described herein.

DFMO has also been shown to induce differentiation in T. brucei (B. F.Giffin, P. P. McCann, A. J. Bitanti and C. J. Bacchi, J. Protozool., 33,238-243 (1986)). This effect is generally attributed to the depletion ofpolyamines. DFMO, however, also causes a 1000-fold increase indecarboxylated S-adenosylmethionine (DSAM) and S-adenosylmethionine(SAM) (A. H. Fairlamb, G. B. Henderson, C. J. Bacchi and A. Cerami, Mol.Biochem. Parasitol. 7, 209-225 (1983)). These latter metabolites areweak chemical methylating agents and, therefore, may be in partresponsible for the differentiating action of DFMO. The depletion ofpolyamines and trypanothione as a result of the DFMO treatment maypotentiate the actions of SAM and DSAM as methylating agents bydecreasing the levels of competing nucleophiles. Depletion of polyaminesmay also make the nucleic acids more susceptible to methylation (R. L.Wurdeman and B. Gold, Chemical. Res. Toxicol., 1, 146-147 (1988)). SAMis also the methyl donor used by many methylases; therefore,enzymatically mediated methylation reactions may also be affected.

Orally active trypanocidal agents are desirable, since in areas wheretrypanosomiasis is endemic, other routes of drug administrationfrequently present problems. Although methylating agents in general aremutagenic, in cases of multi-drug resistant trypanosomiasis which havefailed to respond to existing therapies, these compounds may beextremely effective.

The distinct advantages of methylating agents over existing trypanocidesinclude (a) high therapeutic indices, (b) oral activity, (c) novelmechanism of action, (d) broad-spectrum antitrypanosomal activity, and(e) favorable pharmacokinetics which make these compounds candidates forboth agricultural and clinical development.

The invention will now be described with reference to the followingnon-limiting examples.

EXAMPLES

Melting points were determined on a Thomas-Hoover capillary meltingpoint apparatus and are uncorrected. Proton magnetic resonance spectrawere recorded on a Varian EM-390 spectrometer with Me₄ Si as an internalstandard. Elemental analyses were performed by the Baron Consulting Co.(Orange, CT.) and the data were within 0.4% of the theoretical values.

EXAMPLES 1 to 6 A.1-(2-Methylsulfonyloxy)ethyl-1,2,2-tris(sulfonyl)hydrazines Example 1Preparation of1-(2-methylsulfonyloxy)ethyl-1,2,2-tris(methylsulfonyl)hydrazine

To an ice-cold stirred solution of 2-hydroxyethylhydrazine (6.08 g, 0.08mol) in dry pyridine (40 ml) was added methanesulfonyl chloride (41.2 g,0.36 mol) dropwise, while maintaining the temperature between 0° and 5°C. After keeping the reaction mixture stirred at this temperature rangefor an additional 3 hours, it was left in a freezer (-10° C.) for 48hours. It was then triturated with a mixture of ice and concentratedhydrochloric acid (100 ml, 1:1, v/v). A thick semi-solid separated andsettled at the bottom of the flask. Sometimes a solid separated, whichwas filtered and treated as described below. The clear supernatant wascarefully decanted and the semi-solid was warmed to 60° C. in glacialacetic acid (150 ml) and was cooled to 5° C. The solid that separatedwas filtered, washed with cold glacial acetic acid (20 ml), dried andrecrystallized from ethanol-acetone (1:3, v/v) using Norit A as adecolorizing agent to give 9.6 g (31%) of the title compound: m.p.160°-162° C.; anal.(C₆ H₁₆ N₂ O₉ S₄) C,H,N: ¹ H NMR (acetone-d₆) δ 4.5and 4.1 (2t, 4H, CH₂ CH₂), 3.6 [s, 6H, N² (SO₂ CH₃)₂ ], 3.3 [s, 3H, N¹SO₂ CH₃ ], 3.2 [s, 3H, OSO₂ CH₃ ].

Example 2 Preparation of2,2-bis(methylsulfonyl)-1-(2-methylsulfonyloxy)ethyl-1-(4-toluenesulfonyl)hydrazine

To an ice-cold stirred mixture of1-(2-hydroxyethyl)-1-(4-toluenesulfonyl)hydrazide (6.9 g, 0.03 mol) anddry pyridine (12 ml) was added methanesulfonyl chloride (14.1 g, 0.12mol) dropwise, while maintaining the temperature between 0° and 10° C.After an additional 3 hours of stirring at this temperature range, thereaction mixture was left in a freezer (-10° C.) for 48 hours. It wasthen triturated with a mixture of ice and concentrated hydrochloric acid(100 ml, 1:1, v/v). A thick semi-solid separated and settled to thebottom of the flask. The clear supernatant was carefully decanted andthe residue was boiled with ethanol (100 ml). A solid separated that wasfiltered while the ethanol mixture was still hot, washed with ethanoland dried. It was recrystallized from a mixture of ethanol and acetone(Norit A) to give 4.7 g (34%) of the title compound: m.p. 153°-155° C.;anal. (C₁₂ H₂₀ N₂ O₉ S₄) C,H,N; ¹ H NMR (acetone-d₆) δ 7.9 and 7.4 (2d,4H, aromatic H), 4.4 and 4.0 (2t, 4H, CH₂ CH₂), 3.6 [s, 6H, N(SO₂ CH₃)₂], 3.0 [s, 3H, OSO₂ CH₃ ] and 2.4 [s, 3H, ArCH₃ ].

Example 3 Preparation of2,2-bis(methylsulfonyl)-1-(2-methylsulfonyloxy)ethyl-1-phenylsulfonylhydrazine

1-(2-Hydroxyethyl)-1-phenylsulfonylhydrazide (10.8 g, 0.05 mol) andmethanesulfonyl chloride (29.6 g, 0.26 mol were reacted in dry pyridine(25 ml) and the product was isolated in a manner identical to thatdescribed for2,2-bis(methylsulfonyl)-1-(2-methylsulfonyloxy)ethyl-1-(4-toluenesulfonyl)hydrazine(see Example 2 above): yield, 3.1 g (14%); m.p. 107°-108° C.; anal. (C₁₁H₁₈ N₂ O₉ S₄) C,H,N; ¹ H NMR (acetone-d₆) δ 8.0 and 7.7 (d and m, 5H,aromatic H), 4.3 and 4.0 (2t, 4H, CH₂ CH₂), 3.6 [s, 6H, N(SO₂ CH₃)₂ ],3.0 (s, 3H, OSO₂ CH₃).

Example 4 Preparation of2,2-bis(methylsulfonyl))-1-(2-methylsulfonyloxy)ethyl-1-[(4-methoxyphenyl)sulfonyl]hydrazine

To an ice-cold stirred mixture of1-(2-hydroxyethyl)-1-[4-methoxyphenyl)sulfonyl]hydrazide (10.0 g, 0.04mol) and dry pyridine (25 ml) was added methanesulfonyl chloride (29.6g, 0.26 mol) in portions, while maintaining the temperature between 0°and 5° C. After an additional 2 hours of stirring at this temperaturerange, the reaction mixture was left in a freezer (-10° C.) for 48hours. It was then triturated with a mixture of ice and concentratedhydrochloric acid (100 ml, 1:1, v/v), the clear supernatant was decantedand the thick semi-solid that separated was boiled with ethanol (100 ml)and cooled to 5° C. A yellow solid separated that was stirred withmethylene chloride (200 ml) and filtered. The filtrate was evaporated todryness in vacuo to give the crude title compound, which wasrecrystallized from a mixture of ethanol and acetone (Norit A): yield,6.7 g (34%); m.p. 144°-145° C.; anal. (C₁₂ H₂₀ N₂ O₁₀ S₄) C,H,N; ¹ H NMR(acetone-d₆) δ 7.9 and 7.1 (2d, 4H, aromatic H), 4.3 and 4.0 (2t, 4H,CH₂ CH₂), 3.9 [s, 3H, OCH₃ ], 3.6 [s, 6H, N(SO₂ CH₃)₂ ], 3.0 [s, 3H,OSO₂ CH₃ ].

Example 5 Preparation of2,2-bis(methylsulfonyl)-1-[(4-chlorophenyl)sulfonyl]-1-(2-methylsulfonyloxy)ethylhydrazine

To an ice-cold stirred mixture of1-[(4-chlorophenyl)sulfonyl]-1-(2-hydroxyethyl)hydrazide (12.5 g, 0.05mol) in dry pyridine (20 ml) was added methanesulfonyl chloride (23.68g, 0.21 mol) dropwise, while maintaining the temperature between 0° and10° C. After an additional 2 hours of stirring at this temperaturerange, the reaction mixture was left in the freezer (-10° C.) for 48hours. It was then triturated with a mixture of ice and concentratedhydrochloric acid (100 ml, 1:1, v/v). The solid that separated wasfiltered, stirred with chloroform (300 ml) for 10 minutes, treated withNorit A and filtered. On evaporation of the filtrate to dryness in vacuoa solid was obtained that was recrystallized from ethylacetate-petroleum ether (Norit A) to give 6.3 g (26%) of the titlecompound: m.p. 152°-153° C.; anal. (C₁₁ H₁₇ ClN₂ O₉ S₄) C,H,N: ¹ H NMR(acetone-d₆) δ 8.1 and 7.7 (2d, 4H, aromatic H), 4.5 and 4.1 (2t, 4H,CH₂ CH₂), 3.6 [s, 6H, N(SO₂ CH₃)₂ ], 3.1 [s, 3H, OSO₂ CH₃ ].

Example 6 Preparation of2,2-bis(methylsulfonyl)-1-[(4-bromophenyl)sulfonyl]-1-(2-methylsulfonyloxy)ethylhydrazine

This compound was prepared by reacting1-[(4-bromophenyl)sulfonyl]-1-(2-hydroxyethyl)hydrazide (5.2 g, 0.018mol) with methanesulfonyl chloride (9.0 g, 0.079 mol) in dry pyridine(15 ml) in a manner analogous to that described for2,2-bis(methylsulfonyl)-1-[(4--chlorophenyl)sulfonyl]-1-(2-methylsulfonyloxy)ethylhydrazine(Example 5): yield, 2.5 g, (27%); m.p. 154°-155° C.; anal. (C₁₁ H₁₇ BrN₂O₉ S₄) C,H,N; ¹ H NMR (acetone-d₆) δ 7.9-8.0 (2d, 4H, aromatic H), 4.4and 4.1 (2t, 4H, CH₂ CH₂), 3.6 [s, 6H, N(SO₂ CH₃)₂ ], 3.0 [s, 3H, OSO₂CH₃ ].

EXAMPLES 7 TO 14 B. 1-(2-Haloethyl)-1,2,2-tris(sulfonyl)hydrazinesExample 7 Preparation of1-(2-chloroethyl)-1,2,2-tris(methylsulfonyl)hydrazine

A mixture of1-(2-methylsulfonyloxy)ethyl-1,2,2-tris(methylsulfonyl)hydrazine (2,0 g,0.005 mol), lithium chloride (2.0 g, 0.047 mol) and dry acetone (50 ml)was heated under reflux for 96 hours. The reaction mixture was cooled toroom temperature, filtered and the filtrate evaporated to dryness invacuo. The residue was warmed with chloroform (100 ml) to 50° C.,filtered and the filtrate was evaporated to dryness in vacuo.Recrystallization of the residue from ethanol gave 1.1 g (65%) of thetitle compound: m.p. 154°-155° C.; anal. (C₅ H₁₃ ClN₂ O₆ S₃) C,H,N; ¹ HNMR (CDCl₃) δ 3.6-4.0 (m, 4H, CH₂ CH₂), 3.5 [s, 6H, N² (SO₂ CH₃)₂ ], 3.2(s, 3H, N¹ SO₂ CH₃).

Example 8 Preparation of1-(2-bromoethyl)-1,2,2-tris(methylsulfonyl)hydrazine

1-(2-Bromoethyl)-1,2,2-tris(methylsulfonyl)hydrazine was prepared in amanner analogous to that of the corresponding 2-chloroethyl analogue byreacting 1(2-methylsulfonyloxy)ethyl-1,2,2-tris(methylsulfonyl)hydrazinewith lithium bromide in acetone for 48 hours: yield, 35%; m.p. 147°-148°C.; anal. (C₅ H₁₃ BrN₂ O₆ S₃) C,H,N; ¹ H NMR (CDCl₃) δ 4.0 and 3.6 (2t,4H, CH₂ CH₂), 3.5 [s, 6H, N² (SO₂ CH₃)₂ ] and 3.2 [s, 3H, N¹ SO₂ CH₃ ].

Example 9 Preparation of1-(2-iodoethyl)-1,2,2-tris(methylsulfonyl)hydrazine

1-(2-Iodoethyl)-1,2,2-tris(methylsulfonyl)hydrazine was prepared in amanner analogous to that of the corresponding 2-chloroethyl analogue byreacting1-(2-methylsulfonyloxy)ethyl-1,2,2-tris(methylsulfonyl)hydrazine withpotassium iodide in acetone for 48 hours: yield, 66%; m.p. 136°-138° C.;anal. (C₅ H₁₃ IN₂ O₆ S₃) C,H,N; ¹ H NMR (CDCl₃) δ 4.0 and 3.4 (2t, 4H,CH₂ CH₂), 3.5 [s, 6H, N² (SO₂ CH₃)₂ ] and 3.2 [s, 3H, N¹ SO₂ CH₃ ].

Example 10 Preparation of2,2-bis(methylsulfonyl)-1-(2-chloroethyl)-1-(4-toluenesulfonyl)hydrazine

A mixture of2,2-bis(methylsulfonyl)-1-(2-methylsulfonyloxy)ethyl-1-(4-toluenesulfonyl)hydrazine(2.0 g, 0.0043 mol), dry lithium chloride (2.0 g, 0.047 mol) and dryacetone (50 ml) was heated under reflux for 4 days. The reaction mixturewas filtered and the filtrate was evaporated to dryness in vacuo. Theresidue was warmed with chloroform (100 ml) to 40° C., filtered and thefiltrate was evaporated to dryness. The residue was boiled with ethanol(150 ml) and cooled to 10° C. The unreacted sulfonate which crystallizedwas removed by filtration and the filtrate was evaporated to dryness invacuo. The residue thus obtained was recrystallized fromchloroform-petroleum ether (Norit A) to give 1.2 g (69%) of the titlecompound: m.p. 99°-101° C.; anal. (C₁₁ H₁₇ ClN₂ O₆ S₃) C,H,N; ¹ H NMR(CDCl₃) δ 7.9 and 7.4 (2d, 4H, aromatic H), 3.6-3.9 (m, 4 H, CH₂ CH₂),3.5 [s, 6H, (SO₂ CH₃)₂ ] and 2.4 [s, 3H, ArCH₃ ].

Example 11 Preparation of2,2-bis(methylsulfonyl)-1-(2-chloroethyl)-1-phenylsulfonylhydrazine

A mixture of2,2-bis(methylsulfonyl)-1-(2-methylsulfonyloxy)ethyl-1-phenylsulfonylhydrazine(2.0 g, 0.0044 mol), dry lithium chloride (2.0 g, 0.047 mol) and dryacetone (50 ml) was heated under reflux for 5 days. The reaction mixturewas filtered and the filtrate was evaporated to dryness in vacuo. To theresidue was added chloroform (100 ml) and the mixture was stirred for 10minutes and filtered. The filtrate was evaporated to dryness and thesemi-solid residue obtained was dissolved by boiling in a minimumquantity of ethanol and was filtered. On cooling, the title compound wasobtained as white crystals: yield, 0.68 g (39%); m.p. 114°-115° C.;anal. (C₁₀ H₁₅ ClN₂ O₆ S₃) C,H,N; ¹ H NMR (acetone-d₆) δ 8.0 and 7.7 (dand m, 5H, aromatic H), 3.6-4.0 (m, 4H, CH₂ CH₂) and 3.6 [s, 6H, 2CH₃ ].

EXAMPLES 12 TO 14

The following 1-(2-chloroethyl)-1,2,2-tris(sulfonyl)hydrazines weresynthesized using procedures similar to those described above:

Example 122,2-Bis(methylsulfonyl)-1-(2-chloroethyl)-1-[(4-methoxyphenyl)sulfonyl]hydrazine

Yield, 68%; m.p. 109°-110° C.; anal. (C₁₁ H₁₇ ClN₂ O₇ S₃) C,H,N: ¹ H NMR(CDCl₃) δ 7.9 and 7.0 (2d, 4H, aromatic H), 3.9 (s, 3H, OCH₃), 3.5-3.8(m, 4H, CH₂ CH₂) and 3.5 [s, 6H, (SO₂ CH₃)₂ ].

Example 132,2-Bis(methylsulfonyl)-1-(2-chloroethyl)-1-[(4-chlorophenyl)sulfonyl]hydrazine

Yield, 69%; m.p. 122°-123° C.; anal. (C₁₀ H₁₄ Cl₂ N₂ O₆ S₃) C,H,N; ¹ HNMR (CDCl₃) δ 7.9 and 7.5 (2d, 4H, aromatic H), 3.6-4.0 (m, 4H, CH₂ CH₂)and 3.5 [s, 6H, 2CH₃ ].

Example 142,2-Bis(methylsulfonyl)-1-[(4-bromophenyl)sulfonyl]-1-(2-chloroethyl)hydrazine

Yield, 45%; m.p. 117°-118° C.; anal. (C₁₀ H₁₄ BrClN₂ O₆ S₃) C,H,N; ¹ HNMR (acetone-d₆) δ 7.9-8.0 (2d, 4H, aromatic H), 3.7-4.1 (m, 4H, CH₂CH₂) and 3.6 [s, 6H, 2CH₃ ].

Example 15 C. 1,2-Bis(methylsulfonyl)-1,2-dimethylhydrazine

1,2-Dimethylhydrazine dihydrochloride (2.6 g, 0.02 mol) was suspended inice-cold dry pyridine (6 ml) and the mixture was stirred for 10 minutes.Methanesulfonyl chloride (5.0 g, 0.043 mol) was added in portions tothis mixture, while maintaining the temperature between 0° and 10° C.After an additional 1 hour of stirring at 0° to 5° C., the reactionmixture was left in a freezer (-10° C.) overnight. The pH of thereaction mixture was adjusted to pH 1 with cold dilute hydrochloricacid. The solid that separated was filtered and recrystallized fromethanol (Norit A) to give 1.4 g (32%) of the title compound: m.p.168°-169° C.; anal. (C₄ H₁₂ N₂ O₄ S₂) C,H,N; ¹ H NMR (CDCl₃) δ 3.1 [2s,12H, 2(CH₃ SO₂ NCH₃)].

Example 16 D. 1-Methyl- 1,2,2-tris(methylsulfonyl)hydrazine

To an ice-cold stirred solution of methylhydrazine (4.6 g, 0.1 mol) indry pyridine (30 ml) was added methanesulfonyl chloride (44.6 g, 0.39mol) dropwise, while maintaining the temperature between 0° and 10° C.The reaction mixture was left in a freezer (-10° C.) for 2 days. It wasthen triturated with a mixture of ice and concentrated hydrochloric acid(1:1, v/v, 100 ml). The precipitate that formed was collected, washedwith cold water and dried. This product was stirred with chloroform (200ml) and filtered. The undissolved material, consisting mainly of1,2-bis(methylsulfonyl)-1-methylhydrazine, was discarded and thefiltrate was treated with decolorizing carbon, filtered and evaporatedto dryness in vacuo to give a yellow solid, which was crystallized twicefrom ethanol (Norit A) to give 5.1 g (18%) of the title compound: m.p.123°-124° C.; anal. (C₄ H₁₂ N₂ O₆ S₃) C,H,N; ¹ H NMR (acetone-d₆) δ 3.6[s, 6H, N² (SO₂ CH₃)₂ ], 3.5 (s, 3H, N--CH₃), 3.2 (s, 3H, N¹ SO₂ CH₃).

Example 17 Antineoplastic Activity

The tumor-inhibitory properties of several compounds, e.g.,1,2-bis(methylsulfonyl)-1-methylhydrazine,1-methyl-1,2,2-tris(methylsulfonyl)hydrazine,1,2-bis(methylsulfonyl)-1,2-dimethylhydrazine and1-(2-chloroethyl)-1,2,2-tris(methylsulfonyl)hydrazine were determined bymeasuring the effects of these agents on the survival time of micebearing the L1210 leukemia as described by K. Shyam, L. A. Cosby, and A.C. Sartorelli, J. Med. Chem., 28, 525-527 (1985). The results aresummarized in Table I.

                                      TABLE I                                     __________________________________________________________________________    Effects of Sulfonylhydrazine Derivatives on the                               Survival Time of Mice Bearing the L1210 Leukemia                                                    Optimum effective                                       Compound              Daily Dose, mg/kg.sup.a                                                                 AvΔ Wt, %.sup.b                                                                % T/C.sup.c                                                                        60-day cures,                     __________________________________________________________________________                                                %                                 MeSO.sub.2 N(Me)N(SO.sub.2 Me).sub.2                                                                150       -7.7   186  0                                 MeSO.sub.2 N(Me)N(Me)SO.sub.2 Me                                                                     20       -11.3  158  0                                 MeSO.sub.2 N(Me)NHSO.sub.2 Me                                                                        40       -10.7  180  0                                 MeSO.sub.2 N(CH.sub.2 CH.sub.2 Cl)N(SO.sub.2 Me).sub.2.sup.d                                         60       -7.2   --   100                               MeSO.sub.2 N(CH.sub.2 CH.sub.2 Br)N(SO.sub.2 Me).sub.2                                              150       -2.0   213  0                                 MeSO.sub.2 N(CH.sub.2 CH.sub.2 OSO.sub.2 Me)N(SO.sub.2 Me).sub.2                                    100       -4.2   198  0                                 MeSO.sub.2 N(CH.sub.2 CH.sub.2 I)N(SO.sub.2 Me).sub.2                                               150       +8.0   110  0                                 C.sub.6 H.sub.5 SO.sub.2 N(CH.sub.2 CH.sub.2 Cl)N(SO.sub.2 Me).sub.2                                150       +0.5   187  40                                MeO--4--C.sub.6 H.sub.4 SO.sub.2 N(CH.sub.2 CH.sub.2 Cl)N(SO.sub.2            Me).sub.2             200       +5.9   --   100                               Me--4--C.sub.6 H.sub.4 SO.sub.2 N(CH.sub. 2 CH.sub.2 Cl)N(SO.sub.2            Me).sub.2             150       -12.0  215  60                                Cl--4--C.sub.6 H.sub.4 SO.sub.2 N(CH.sub.2 CH.sub.2 Cl)N(SO.sub.2             Me).sub.2             200       -3.4   203  60                                Br--4--C.sub.6 H.sub.4 SO.sub.2 N(CH.sub.2 CH.sub.2 Cl)N(SO.sub.2             Me).sub.2             150       +0.9   241  60                                __________________________________________________________________________     .sup.a Administered once daily for 6 consecutive days, beginning 24 hours     after tumor transplantation with 5-10 animals being used per group.           .sup.b Average change in body weight from onset to termination of therapy     .sup.c % T/C = average survival time of treated/control animals ×       100.                                                                          .sup.d % T/C vs. P388 leukemia = 218 (80% 60day cures) at 60 mg/kg/day   

The methylating agents displayed considerable activity against thistumor and the chloroethylating agent [MeSO₂ N(CH₂ CH₂ Cl)N(SO₂ Me)₂ ]was exceedingly active, giving 60-day "cures" of the L1210 leukemia atlevels of 40 and 60 mg/kg per day x 6. Replacement of the chloroethylgroup in MeSO₂ N(CH₂ CH₂ Cl)N(SO₂ Me)₂ by bromoethyl ormethylsulfonyloxyethyl resulted in retention of activity against theL1210 leukemia, the compounds giving maximum % T/C values of 213 and 198percent, respectively. Activity was abolished when the chloroethyl groupwas replaced by iodoethyl.

A single intraperitoneal dose of 1.2 g/kg or six daily intraperitonealdoses of 200 mg/kg of MeSO₂ N(CH₂ CH₂ Cl)N(SO₂ Me)₂ produced nolethality in normal mice. Thus, the relatively great efficacy of thiscompound against the L1210 and P-388 leukemias and its relative lack oftoxicity makes it an agent of significant promise.

Example 18 Trypanocidal Activity

The trypanocidal properties of several methylating agents includingMeSO₂ N(Me)N(SO₂ Me)₂ and MeSO₂ N(Me)N(Me)SO₂ Me were determined bymeasuring their effects on the survival time of CD-1 mice infected withT. rhodesiense (Y Tat 1.1), a pleiomorphic strain that produces anon-replapsing disease in mice. The level of parasites in thebloodstream and body fluids increases by approximately 10-fold per dayand the animals die when the parasite burden exceeds 1 to 2×10⁹cells/ml. Infection with a single viable parasite will kill a mouse inapproximately 9 to 10 days.

Mice were infected ip with approximately 10⁶ trypanosomes/mouse inphosphate buffered saline containing glucose. This level of parasitesproduces death in 4 days post-infection. These mice were treated (ip)with a single dose of drug dissolved in the appropriate vehicle 3 daysafter infection, when the parasitemia was 1 to 3×10⁸ cells/ml of bloodand the mice, if untreated, would survive for only 24 additional hours.The number of days the mice survived beyond that of the untreatedcontrols was used as a measure of trypanocidal activity. The level ofparasitemia in treated mice was measured at regular intervals todistinguish between parasite-related and drug toxicity-related deaths.No toxic deaths were observed. Mice that survived for 30 days withoutdetectable parasitemias were considered cured. The effects of a singledose of various methylating agents on the survival time oftrypanosome-bearing mice are summarized in Table II.

                  TABLE II                                                        ______________________________________                                        Effects of Methylating and Ethylating Agents on                               the Survival Time of Mice Bearing T. rhodesiense                                                 Dose      Mean Extension                                   Compound           (mmol/kg) of Life (Days)                                   ______________________________________                                        MeNHNH.sub.2 .sup.a                                                                              0.5       1                                                MeNHNHMe.sup.a     0.2       4.3                                              EtNHNHEt.sup.a     0.2       0                                                MeSO.sub.2 N(Me)NHSO.sub.2 Me.sup.b                                                              0.2       11.8                                             MeSO.sub.2 N(Me)NHSO.sub.2 C.sub.6 H.sub.4 -p-OMe.sup.b                                          0.2       4.5                                              PhSO.sub.2 N(Me)NHSO.sub.2 Ph.sup.b                                                              0.2       5.0                                              MeSO.sub.2 N(Me)N(SO.sub.2 Me).sub.2 .sup.b                                                      0.2       7.7                                                                 1.0       100% cure                                        MeSO.sub.2 N(Me)N(Me)SO.sub.2 Me.sup.b                                                           0.2       25% cure                                                                      9.7 for relapsing                                                             animals                                          Me.sub.2 SO.sub.4.sup.b                                                                          0.2       3.0                                              Et.sub.2 SO.sub.4.sup.b                                                                          0.2       0                                                MeSO.sub.2 OME.sup.b                                                                             0.2       1.0                                              N-Methyl-N-nitrosourea.sup.b                                                                     0.2       8.0                                              Procarbazine.sup.a 0.2       5.0                                              DTIC.sup.a         0.2       6.0                                              Streptozotocin.sup.a                                                                             0.2       4.3                                              ______________________________________                                         .sup.a Drug that was administered was dissolved in 0.5 ml of phosphate        buffered saline containing glucose.                                           .sup.b Drug that was administered was dissolved in 0.05 ml of DMSO.      

As mentioned above, compounds lacking a reactive methyl group(s), butstructurally identical in all other respects, or containing the reactivemethyl group(s) but lacking good leaving groups, were inactive andfailed to generate methanol in phosphate buffered saline (Table III).

                  TABLE III                                                       ______________________________________                                        Structural Requirements for Antitrypanosomal Activity                         Compound                                                                      Administered in                                                                             Mean Extension                                                                             Relative Methanol                                  0.05 ml of DMSO                                                                             of Life (Days)                                                                             Generation in vitro                                ______________________________________                                        PhSO.sub.2 N(Me)NHSO.sub.2 Ph                                                               5            1.0                                                PhSO.sub.2 NHNHSO.sub.2 Ph                                                                  0            0                                                  PhCON(Me)NHCOPh                                                                             0            0                                                  ______________________________________                                    

Methanol was produced by these agents in aqueous solutions free fromstrong competing nucleophiles. Formation of this alcohol was used as ameasure of the rate of spontaneous breakdown of these compounds togenerate reactive methyl groups. When aqueous buffered (pH 7.6)solutions of 1,2-bis(methylsulfonyl)-1-methylhydrazine were assayed overtime for the formation of methanol, no further alcohol was generatedafter 15 minutes, indicating that decomposition was complete within thistime period. This result correlated with the loss of biological activityupon aging of equivalent solutions, where essentially all antiparasiticactivity was lost after aging for 15 minutes, (i.e., 0, 21, 73 and 97%of the antitrypanosomal activity was lost after 0, 1, 5 and 15 minutesof aging, respectively). These findings provide strong evidence thatmethylation is essential for the observed biological activity of thesecompounds. In support of this hypothesis, a number of structurallyunrelated methylating agents, but not ethylating agents were found tohave significant biological activity (Table II).

The absence of clear-cut structure-activity relationships is probablydue to the large number of variables introduced in vivo test systems andmay reflect variation in parameters other than stability and rate ofgeneration of the alkylating species.

A representative agent, 1,2-bis(methylsulfonyl)-1-methylhydrazine, wasalso tested against several other trypanosoma species. Activity has beendemonstrated against T. gambiense which, like T. rhodesiense, causes afatal disease in man, and against I. brucei brucei, T. evansi and T.equiperdum, which are species of veterinary importance.

The therapeutic indices of some of the invented compounds aresignificantly greater than that of the antineoplastic agents tested forantitrypanosomal activity; for example, cures are obtained with1,2,2-tris(methylsulfonyl)-1-methylhydrazine at approximately 10% of theLD₅₀, whereas animals given streptozotocin at 50% of the published LD₅₀survived for only 4 to 5 days longer than the control animals.Preliminary results indicate that1,2-bis(methylsulfonyl)-1-methylhydrazine,1,2,2-tris(methylsulfonyl)-1-methylhydrazine and1,2-bis(methylsulfonyl)-1,2-dimethylhydrazine have comparable activityto that reported in Table II when administered orally in aqueoussolutions. The decomposition of1,2-bis(methylsulfonyl)-1-methylhydrazine in aqueous solutions can beinhibited by dosing in acidified solutions. Orally active trypanocidalagents are desirable since, in areas where trypanosomiasis is endemic,other routes of drug administration frequently present problems.

It will be appreciated that the instant specification and claims are setforth by way of illustration and not limitation, and that variousmodifications and changes may be made without departing from the spiritand scope of the present invention.

What is claimed is:
 1. A pharmaceutical composition comprising as anactive ingredient a trypanocidal effective amount of1,2,2-tris(sulfonyl)-1-methylhydrazine of the formula R'SO₂ N(CH₃)N(SO₂CH₃)₂, wherein R' is an alkyl having 1 to 10 carbon atoms or an aryl, inadmixture with a solid, liquid, or liquefied gaseous diluent.
 2. Apharmaceutical composition according to claim 1 in the form of a sterilephysiologically isotonic aqueous solution.
 3. A pharmaceuticalcomposition according to claim 1, in the form of a tablet, pill, dragee,capsule, ampoule, or suppository.
 4. A pharmaceutical compositioncomprising as an active ingredient a trypanocidal effective amount of1,2-bis(sulfonyl)-1,2-dimethylhydrazine of the formula R"SO₂N(CH₃)N(CH₃)SO₂ R", wherein R" is an alkyl having 1 to 10 carbon atomsor an aryl, in admixture with a solid, liquid, or liquefied gaseousdiluent.
 5. A pharmaceutical composition according to claim 4 in theform of a sterile physiologically isotonic aqueous solution.
 6. Apharmaceutical composition according to claim 4, in the form of atablet, pill, dragee, capsule, ampoule, or suppository.
 7. A method oftreating trypanosomiasis in a warm-blooded animal patient comprisingadministering to said patient a trypanocidal effective amount of amethylating agent, wherein the methylating agent is selected from thegroup consisting of(a) R'SO₂ N(CH₃)N(SO₂ CH₃)₂, wherein R' is an alkylhaving 1 to 10 carbon atoms or an aryl and (b) R"SO₂ N(CH₃)N(CH₃)SO₂ R",wherein R" is an alkyl having 1 to 10 carbon atoms or an aryl.